Centrifugal clutch



4July 4, 1950 M. L. HATFIELD CENTRIF'UGAL CLUTCH Filed April 28, 1947 N: Q 2 u l1* 3 n v `5 y N ENTQ QQ' MILTON L. HATHELD ATTO RNEYS Patented July 4, 1950 "UNITED @PATIENT OFFICE CErrrRIrUGALy 'CLUTCH y Milton L. Hatfield, Elkhart, 1nd. Application April 28, 194K?,v Serial'No.'744,350

l The present invention relates to a clutch of the centrifugal type. It is an object and purpose of the invention to provide a clutch structure, interposed between driving and driven members, in which said members are automatically connected together upon the attainment of apredetermined speed `of the driving member,- and more particularly to provide a simple and novel clutch'structure of the character stated, wherein the engagement and connection of driving and driven members may be adjusted to vary the predetermined speed of the driven member- `at'which the clutch connection occurs. f

It is a further object of the invention to provide the adjustable centrifugal clutch in a structural embodiment which is very economical to produce, durable in service, and particularly effective for the purpose for which it is designed. Such type of clutch is particularly useful, for example, in. small motor-driven vehicles of the scooter type, driven by an internal combustion engine of low horse-power, wherein the connection with the driven axle and wheels of the scooter is obtained by speeding up the engine beyond a certain speed, and the clutch is automatically disconnected on diminishing such speed of rotation below the particular engine speed for which the clutch adjustment has been made. It is of course, understood that the clutch is useful in other relations than in small motor vehicles, and

its use is not to be restricted to the one example given. A further object of the invention is to provide means automatically disengaging the clutch at any time the power is cut 01T.

An understanding of the invention may be had from the following description, taken in connection with the accompanying drawing, in which,

Fig. 1 is a vertical section substantially on the plane of line I-I of Fig. 2,

Fig. 2 is a central transverse vertical section through the clutch, substantially on the broken plane indicated by the line 2-2 of Fig. 1.

Like reference characters refer to like parts in the different gures of the drawing.

In the drawing showing a preferred structure embodying my invention, a shaft I which will be a driven shaft, has keyed thereto a hub 2 which, while shown as formed has a pulley adapted to have a V-belt associated therewith, for the invention may be merely a hub without having connected therewith any means for driving a belt therefrom The hub at its inner side is continued and terminates in an annular drum 3, the flange of which is concentric about the axis of th shaft I.

.. .2lClaims. (Cl. 1532-105) -Ontheshaft I, 'outwardly of the hub 2, a second hub 4 is' loosely mounted from which an annular' circular web 5 extends, and is continued as an integral rflange 6 continuous except 'for a section at 6a (Fig. l) cut-therefrom; From the outer edges of ythe 'annular flange y6, anoutwardly extending circular vertical wall 'I'isprovided which terminates in a return flange and pulley 8 around the drum 3 lspaced therefrom and concentric about the axis of the shaftl. Thefouter side of the flange 6 is closed by a cover plate 9.1i.' l'

i A yband I 2-1 'of flat-metal Vis permanently' secured adjacentone endtov the Alange' at'one'side of the recess 6a therein. It is located around the flange 6 as shown in Fig. 2. The band extends to and partly over the opening at 6a at the other end thereof. At its outer side it carries a band or shoe I3 of friction brake or clutch material which is located within and closely adjacent to the inner walls of the drum 3.

A sleeve 4a is loosely mounted on the outer end of the shaft Il and may rock thereon. On the sleeve 4a and integral therewith is a radially extending weight I6 and diametrically at the opposite side of the spring an arm I1, in partial counter balance of the weight I6, narrowed in width at its inner portion and having a pin I8 extending therefrom to which the inner end of the spring I4 is connected, said spring at its outer end being connected to the band I2 at its free end. A lug I9 extends from the sleeve 4a, through which a screw 2B is adjustably threaded, with its end coming against a post 2I cast with and projecting outwardly from the web 5. It is apparent that the tension of the spring may be adjusted by adjusting the screw 20.

In the operation, the pulley 8 having a belt around it connected with any suitable source of rotative power, when rotating in the direction indicated by the arrow in Fig. 1, will cause the annular ange 6 to rotate, and the bands I2 and I3 will tend to be thrown outwardly by centrifugal force. Upon the attainment of a suicient speed to overcome and stretch the spring I4, the outer side of the clutching band I3 will press against the inner annular side of the drum 3 and a connection be made, whereupon said drum, the hub 2 and shaft I will be driven with the same speed of rotation as the hub 8.

When the speed drops below that at -which the centrifugal force is effective to press the band I3 against the drum 3, an automatic disconnection between the driving pulley i8 and the driven drum 3 occurs. The adjustment of the tension of the spring I4 is availed of to control such connection counter weights I6 and I-8 aid in quick disengagement of the clutch. The counter weights riding freely within the clutch tend to continue their `rotation ewhen the clutch rotation is sharply reduced. As may appear from lan example, if thel ffj 2,513,79s

engine is turning at 2,000 R. P. M., with the clutchengaged, if the engine power is cut off, the:

counter weights tend to continue at rst at the speed of 2,000 R. P. M. and do not deceler'ate as AS a result, the spring I4` atfast as the engine. tached to the counter weight increases in tension a quickly controlled clutch disengagement.

The construction is one which is readily and of structure coming within their scope.

IlClam: j 1. A pulley driven clutch comprising, a, shaft, fa circular drum xed to said shaft, a pulley loosely and balances its centrifugal force, resulting 'in 4 mounted on said shaft, a friction band located closely adjacent the inner surface of said drum, and having one end xed to said pulley, fa weighted member loosely mounted yon said shaft, means coacting between said pulley land said weighted member for positively driving the member in the direction of rotation of the pulley, said member being free to rotate in said direction faster than rotation of the pulley uponJ deceleration of the pulley, vand av spring connecting said weighted member with the' free end of said friction band.

2. The elements of claim 1 in which the fixed end of said friction band is in advance of the free end thereof in the direction of rotation.

MILTON L. HATFIELD.

REFERENCES CITED The following references are of record in the le of this patent:

' 'UNITED STATES 'PATENTS Number v Name vDate 678,838 -Lefener July 16, 1901 882,693 Kingsbury Mar. 24, 1908 1,451,506 Graf et'al Apr. 10, 1923 '1,762,799 Starkey June 10', 1930 1,983,661 Frantz et a1 Dec. 11, 1934 '2,087,488 'Stanley July 20, 1937 f u FOREIGN PATENTS y y Number Country Date Great Britain Mar. 27, 1933 

